Traffic engineering Q The data from moving observer methods as shown in the table. Column 1 gives the sample number, column 2 gives the number of vehicles moving against the stream, column 3 gives the number of vehicles that had overtaken the test vehicle, and last column gives the number of vehicles overtaken by the test vehicle. Find the flowrate, density and mean speed. Also, plot the fundamental diagrams of traffic flow. 2 3 4 No. Sample 1 107 10 74 2 113 25 41 3 30 15 5 4 79 18 9

Traffic engineering Q The data from moving observer methods as shown in the table. Column 1 gives the sample number, column 2 gives the number of vehicles moving against the stream, column 3 gives the number of vehicles that had overtaken the test vehicle, and last column gives the number of vehicles overtaken by the test vehicle. Find the flowrate, density and mean speed. Also, plot the fundamental diagrams of traffic flow. 2 3 4 No. Sample 1 107 10 74 2 113 25 41 3 30 15 5 4 79 18 9

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

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Results of traffic flow studies on a highway indicate that the flow-density relationship can be described by the expression. Us q=uck - If speed and density observations give the data shown below, develop an appropriate expression for speed versus density for this highway. (Use the following as necessary: k. Assume u is in mi/h and k is in veh/mi. Do not include units in your answer.) Speed (mi/h) Density (veh/mi) 11 ufk² kj 57 53 45 39 28 21 18 density at maximum volume 21 22 39 60 70 86 97 Determine the density (in veh/mi) at which the maximum volume will occur as well as the value of the maximum volume (in veh/h). 80 X Your response differs from the correct answer by more than 10%. Double check your calculations. veh/mi
4-5 An engineer wishing to determine whether there is a statistically significant difference between the average speed of passenger cars and that of large trucks on a section of highway, collected the data shown below. Determine whether the engineer can con- clude that the average speed of large trucks is the same as that for passenger cars. Average Speed (mi/h) Standard deviation of speed ± mi/h Sample size Trucks 62 5.5 275 Passenger Cars 59 6.3 175
1. A study of speed-flow-density relationships at a particular site has resulted in the following calibrated equation and graph 1:- (a) Assuming a linear relationship, derive the equations depicting the relationship between flow and density and speed and flow, for this site. (b) How long will it take for the last vehicle queued during the red phase to clear once the light turns green? Speed km/h 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 0 20 ū = 71.2 (1-122) Speed vs Density Curve 40 80 60 Density veh/km GRAPH 1 100 120 140
Match the following to True/False. A. GPS devices are an example of mobile traffic sensors For the time-space diagram of a single-lane one-way road, the vehicle trajectories do not intersect with each other unless there is a crash. Pneumatic tubes detect vehicle presence by sending an electric signal to a roadside device. B. Space mean speed may be greater than time mean speed in certain situations. A. True B. False
Q1. During a 60 seconds period, a loop detector is occupied by vehicles for the following times for the following, 0.34s (car1), 0.38s (car2), 0.40s (car3), 0.32s (car4) and 0.52s (car5). Estimate the value of flow, density and velocity. You can assume that length of the loop detector is equal to 10 feet and the average length of all vehicles is 20 feet. Vehicle Ground Loop Detection Circuit Ż
From data collected on a metropolitan arterial road, it has been found that speed (v in kph) and density (k in vpk) are related by the following expression: v=72 0.72k Plot the speed-density diagram. Write the equation of the plot on this diagram and show the values of free-flow speed, critical speed, critical density and jam density on this diagram. Plot the flow-density diagram. Write the equation of the plot on this diagram and show the values of free-flow speed, critical speed, critical density, jam density and capacity on this diagram. Plot the speed-flow diagram. Write the equation of the plot on this diagram and show the values of free-flow speed, critical speed and capacity on this diagram.
4. The relation of the density (d) along a roadway to vehicle speed (s: km/h) is given as d = 50- s/2 Determine the flow (q)-speed (s) and flow (q)-density (d) relationships and draw the variations of density-speed, flow-speed and flow-density on. Show the maximum and minimum points on these graphs
Assume you are observing traffic in a single lane of a highway at a specific location. You measure the average headway and average spacing of passing vehicles as 3.2 seconds and 20 m, respectively. Calculate the flow, average speed, and density of the traffic stream in this lane.
The primary elements of traffic flow are flow, density, and speed. Discuss with illustration the relationships between the three elements of a traffic flow.
By employing linear regression on the field data for speed and density in the table below, find the macroscopic flow equation assuming the traffic flow follows to greenshield model. Calculate the free mean speed, jam density, and maximum flow. Speed (km/h) Density (veh/km) 53.2 20 48.1 27 44.8 35 40.1 44 37.3 52 35.2 58 34.1 60 27.2 64 20.4 70 17.5 75 14.6 82 13.1 90 11.2 100 8.0 115
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